jochen-hoenicke.de and blockchair.com charts. What's wrong with them yesterday?

[tranthidung]

I check jochen-hoenicke.de website [1] every day and yesterday, it did not display the visual chart (all in plain white background). Today it works again but those charts have some dips to zero at one point. I thought it is technical problems from the website or its related full node.

I double checked with blockchair.com [2] and found a sudden drop of transaction count.

What happened with them?

[1] https://jochen-hoenicke.de/queue/#BTC%20(default%20mempool),24h
[2] https://blockchair.com/bitcoin/charts/transaction-count

[ranochigo]

Looks like the mempool site went down for a bit.

The blockchair chart appears to be fine though. I'm not too sure about the updating interval but it looks like it dips to zero today which could be due to them not displaying the transaction count on 23/2/2021.

[DdmrDdmr]

There were a couple of similar issue back in October 2020:
What happened here? jochen-hoenicke.de.
Confusing a website's mempool stats with the Bitcoin network

Both point to a node restart being the likely reason behind the glitch, although the one shown on the image here is weird, as the datapoints show a descending regular line between somewhere before 00:00 and after 04:00 which is different to the behaviour on those other referenced cases.

Can’t see the effect displayed on the first image on the live site now.

Edit:

<...>

True. The node seems to have been unreachable for a longer period of time than on prior occasions, thus the descending regular line over different data points that connect last read with restart of readings (presumably from the near 0 baseline).

[o_e_l_e_o]

The graphs on Jochen's site were completely empty for most of yesterday, so it seems simply that that node being used was offline for a while. The next data point being when it went back online with an empty mempool caused the weird looking straight line down until it received all the unconfirmed transactions from other nodes again.

Interestingly, the non-default mempool graph, which you can select by clicking n BTC at the top, looks normal. He must be sourcing the data from two different nodes.

[Bitcoin_Arena]

Once in a while I also see anomalies on mempool.space except that the dips in their graph are usually sharp as compared to those in  jochen-hoenicke.de website.
I believe both deeps happened at the same time which make me wonder. Do all this website source from the same node/nodes?

[ranochigo]

but as for node of blockchair.com, i speculate many transaction was dropped (one possible reason is the transaction is on mempool more than 2 weeks) because the transaction count isn't dropped to 0.

Isn't that due to them not updating the chart in real time? By using a smaller interval, the transaction count on the day itself is always zero and if you check it the next day, it'll be as per normal. The reason why it looks like there's a huge drop only happens if you select a larger interval and the (0) transaction count on the day itself affects the chart towards that day.

https://blockchair.com/bitcoin/charts/transaction-count?granularity=date&interval=3m

[ranochigo]

It's possible, but even using small interval (last month), the lowest value on Y-axis is 170000, not 0.

Yes. It's only 0 on the day itself. They only update the transaction count the following day.